Automatic take-up mechanism



Sept- 1 1932 .J. A. CASALETTO AUTOMATIC TAKE-UP MECHANISM Filed Oct. 6. 1930 I VENTOR.

ATTORNEYS.

H @WW flw & V R

Patented Sept. 13, 1932 some Ahmad-10F nos slats," CALIFORNIA" suroira'rrcj mass; Masa -ma a plication has octet -re, 1e3'e Serial li 486,714, This invention relates to brake mechanisms for vehicles and the l1ke, and particularly to means whereby wear of the brake shoes-and connected operating mechanism is automaticallytaken-up. r v 1 Ordinary brakes as used on automobiles and; like vehicles, consist of brake drums,

bands or shoes movable into and out of en gagement'therewith, and a series of leversand links whereby-the bands or shoes are v actuated either bya foot pedal or a brake lever.

movement, of y the foot pedal increases pro portionately until a. point is reachedwhere theffoot pedal actually engages the foot boards where further movement is stopped.

'If the average drivefwould immediately, or

at least withi-n the next;dayor' two, see; to it that the brakes were readjusted, 'oor inother words, take up the slack-caused by wear, se

wait too long and the first thing hekn'ows an emergency arises where responsive andpositive action of the brakes is required. The

brakes and connected mechan sms are too slack and as such do notrespondj as quickly as they should and the result is a rear end collision, a pedestrian is rundown, etc;

The object of the presentinvention is to overcome the objections above referred to by providing means-for automatically taking up slack as it develops. The invention, more specifically stated, comprises a brake'pedal or the like, a link mechanismconnecting the pedal and brake mechanism to be actuated,

and means interposed inthe link connection whereby slack is automaticallytaken up as wear takes place.

- Fig. 1 is a plan view showing the manner in which the automatic take-up is applied to the brake mechanism of an automobile,

Fig. 2 is a side elevation of the take-up mechanism and the foot pedal whereby it is .tion of the take-up duringappli The foot pedal, .togetherwith thebrake bands or shoes. actuated thereby, are in con stant use and are subject to considerablewearand as wear; gradually increases, the I instance is indicated atF. a shaft 8 in the usual manner and this shaft actuated, said view showing mechanism in releasedposi'tion, I F 1g. 31s av sinnlarvlcw showing theposlt e Jak t cation'of the brake," I v, a Fig. 4 is a cross section taken on line IV- IVof Fig.2. y Y Referringto the drawing in detaillandparticularly Figs. 1' to 3, A indicates the frame of a m otorvehicle',B the f'rea'r wheels equipped with the usualbrake drums and i bands or shoes, G the brake actuating shafts, D the equalizer, and E the link whereby movement is transmitted from the foot pedal Ftothe equalizer. I The take-up mechanism forming the subject matter of the present application is best a I illustratedin'Figs; 2 to 4:, inclusive. QIt con- 'sists'of an elongated flat plate, the center portion of which is cut out to. formupper and v 1 a lower rack teeth as indicatedat 3 and ,4.

. Rack teeth are also cutzonthe lower edgeof the plate as indicated at 5 audit should be ,noted that the teeth 3 and 4 are staggered r1ous results and accidents would'be p ne-F 'with relation to each otherso as to be intera, "vented. The'averagednver Wlll, however,

'Inittently engaged by pawlsfi and as will hereinafter be describedQ V l g y The foot pedal employed in the present a It is, secured on carries a crank'arni 9.3'lhei1pper end of the crank arm is pivotally connected as atlO with fa rod 11 andfthis is, connected with-a head member12 which carries the paw/1S6 and 7,- these pawls being maintained in en- V 55 gageine'nt' with one setofrack teeth or another through means'ofspringarms13. 'Pivotall y secured to the crank arm 9 as, atl lat v a POIHU below the pivotal connectionlO is a second rod 15. This frodterminates-in a pawl '16 which engages thera'ck teeth 5 and I the pawl is 'heldin engagement with said r teeth byrneans ,ofa'fiat spring arm 17. The ThB IHVBDUOII is shown by way of illustra-- @1011 in the accompanylng drawing, in which rods 11 and 15, together ,with the, pawls 6 and-7, are heldagainst lateral movement by side-plates 18 and 19, which are connected at their lower edgebya bottom platesl 8 and 19 are secuwd to such forms ahousing which secures therods 9 and pawls against lateral movement, the bottom portion 20 of the plates at the same time functioning as a Support for the sprlng 17 The take up mechanism just described is interposed in the link E. That IS, in ordinary plates link E extendsito} the crank arm i 9 and is'there pivotally secured, In the pres- V cm instance, link E is cut short and connected to the take-up mechanism at the point indicated at 23 and the rods 11 and 15 form the other connection. In actual practice, Fig. shows a normal position of the brake pedal,

that is the position in which the brakes are released, and Fig.3 shows braking POSltlOIh:

sition'due to'the tension of the pull-back} springs indicated at G." In normalg eration awl 16 does not function itmerely slides ack and forth on one or another of thelrack teeth 5, but as the brake mechanismisin continuous use and wear gradually accumulates the stroke or movement oi the foot pedal 1ncreases; It should be noted that the distance from thejcenter point of shaft 8 to the connection 14 is' less than the distance to the connecf tion 10, hence when the brake pedal is dc.

' npawls carried by sald rod and engageable .upon sliding movement ofi the rod, one with pressed rod 11 will move a greater distance 7 40 than rod 15. In otherwords, rod 11 tends to pull the'take-up mechanism, together with the I link E, in the direction of arrow a, see Fig. 9 agreater distance than the travel of rod 15 with connected'pawl 16, hence pawl 16 slides rearwardly with relation to the tooth ithappens to engage and when the wear of the brakes and the connected mechanism exceeds a cer tain'orpredctermined amount the brake pedal will be moved to a position where pawl .16 will finally slip over the tooth it happens to engage and thus take-up that much. slack. When the brake pedal is released, if pawl 16 has connected a tooth the pull-back springs G.-

will return the rack bars a' greater distance than waspreviously the case, hence rod, 11,.together with the pawls 6 and 7 carried thereby, will move in a direction oppositeto arrow a and pawl 7 will bereleased while pawl 6 will move into engagement with the next tooth or that indicatedat 6a. The rack teeth 3, and 4 are staggered with relation to each other thus causing the pawls 6 and 7 to intermittently engage.

permits the automatic take-up mechanism to 'sion;

This is important as itpermits av closer spa'cingof the rack teeth 5 and thereby automatically take-up wear at shorter intervals than would otherwise be possible.

While the automatic take-up mechanism has been shown and described as applied to the brake mechanism of an automobile or the like, it obvious. that it may be applied wherever a brake'mech'anism is employed, for

instance, on winches, brake actuated hoists,

etc, and while certain features of the present invention are more 'or' less specifically described, I wish it understood that various changes may be resorted to within the scope of the appended claims. Similarly, that the materia s and finishes of the several parts employed may be such as the manufacturer I y decide, orvarying conditions oruses may e mend.

Having thus described my invention,'what I claim and desire to secure by LettersgPat entis j 1. A brakemechanism comprising a brake,

a brake lever, a pivot'ally mountedshaft to which the brake'lever is secured, a crank arm secured on' said shaft and movable in unison with the brake lever, a pair of rods'pivotally connected to said crank arm, one at the outer onthe outermost rod 'engageable with-oriejof said rack-bars, a pawl onthe inner rod enga 2., In a braketake-up device of thecharacendthercof and one at'a point'intermediate the shaft and the 'outer'end, a take-up device" including apair of toothed rack bars, a pawl ter described, a double ra'ck bar having oppositely-disposedrows of teeth',a rod slidable within said doublerack bar, and a pair. of

each of said rows ofteeth.

ter described, a double rack bar having oppositely disposed rows of teeth, a rod slidable within said'double rack bar, and a pair of pawls carried by said rod and engageable I 3. In a brake take-up device of the charac'" upon sliding movement of the rod, one with each of said rows of teeth inalternate succes- 

